2013 550xi ticking/knocking

[alittletrouble]

Hey guys, I am not very active on this website, but I was hoping I could get the thoughts of people that know a bit more than I do. I have been trying to get my friend into cars since I met him and I think it has finally worked. We have been searching Facebook Marketplace for a quick car so that we can go to car meets and go on cruises together, and we have found a 2013 BMW 550xi. We went out to take a look at it, and the guy that owns it has been very upfront with us. He swears to God that the car needs a new engine, but I am not totally convinced. It is a stock car, other than a transmission tune that he has on it (I don't remember what he had called it, but he made sure I knew it wasn't an ECU tune). It fires up, runs, drives, and doesn't even have a check engine light. It does, however, have a knocking sound coming from the front passenger side of the engine bay. As far as knocking goes, it is pretty quiet, and arguably could be described as ticking instead. If I knew how to upload the video I would. I asked my dad, who is not a licensed mechanic but I have never found a car issue that we couldn't fix in the driveway on some jack stands, and he said it sounds like lifter tick. Considering the owner is an actual mechanic (not very old, maybe 22 years old), I am hesitant on who to trust. If anyone had any information that would be really helpful, thanks in advance.

[PanzerShrekd]

Do you have a video of it? BMW injectors are extremely clicky. The N63 also has issues with fuel injectors and possible spun rod bearings. What is mileage? Can you get a look at any of the used oil for metal?

[alittletrouble]

I do have a video of it but I don't know how to upload it, the only way it says I can upload a video is from youtube or facebook with a URL. Spun bearings could be the issue, I sent the video that I do have to my cousin who is a diesel mechanic and he said the same thing. It has 100,000 miles but I don't think he'd entertain me if I asked him if I could look at the used oil. Also, the injectors sound normal to the best of my knowledge.

[PanzerShrekd]

I do have a video of it but I don't know how to upload it, the only way it says I can upload a video is from youtube or facebook with a URL. Spun bearings could be the issue, I sent the video that I do have to my cousin who is a diesel mechanic and he said the same thing. It has 100,000 miles but I don't think he'd entertain me if I asked him if I could look at the used oil. Also, the injectors sound normal to the best of my knowledge.

You can do a blackstone labs sample of the oil for $30. If you are also able to take a screwdriver and press it to your ear in various locations of the engine you should be able to pinpoint it more closely.